Anatomy of a live invertebrate revealed by manganese-enhanced Magnetic Resonance Imaging.

Non-invasive imaging technologies such as Magnetic Resonance Imaging (MRI) are increasingly in demand by researchers in many biological disciplines. However, when imaging small animals such as invertebrates, not only is the use of high-field magnets necessary to gain satisfactory spatial resolution, but the achievement of adequate contrast between tissues also requires the identification of applicable imaging parameters by means of expensive and time-consuming procedures. Here we report that systemically administered manganese can act as an effective MRI contrast agent for quick and non-invasive imaging of the nervous system and other complex anatomical structures in a small aquatic animal. Due to the tendency of manganese ions to differentially accumulate in most soft tissues, higher overall signal intensity and strongly improved contrast between structures yield data well suited for digital post-processing into three-dimensional models. Within a few hours this technique can efficiently generate anatomical images that are not obtainable with conventional methods, thus demonstrating a new and exciting approach to invertebrate research.